The clamps for the sample key and the blank are usually mounted on a carriage which is both swingable and slidable with reference to a frame carrying the cutting wheel and the feeler. For the shaping of key profiles with steep flanks it is convenient to have a single handle controlling both movements of the carriage, e.g. as described in German Pat. No. 1,953,911 in which such a handle is designed as a two-arm lever fulcrumed on the carriage, the short lever arm constituting a sector gear in mesh with rack teeth on a guide bar centered on the swing axis. The relative mobility of the clamp support and the frame in two dimensions, i.e. radially and axially with reference to the cutter axis, allows faithful reproduction of the bit contour in only one plane; if the key bit is of appreciable thickness, its ridges and groove bottoms show a distinct concavity conforming to the curvature of the cutting wheel.
For greater wear resistance, it would be preferable to form these ridges and groove bottoms with convex rather than concave curvatures. Moreover, special keys for safe-deposit boxes or the like are sometimes characteristically profiled in both a longitudinal and a transverse direction, e.g. with lands sloping at various angles relatively to an axial plane.